Alongside maintaining a nutritious diet and regular physical activity, ensuring sufficient sleep is a fundamental pillar of a healthy lifestyle. However, were you aware that sleep can also pose significant risks?
Numerous issues can arise when you close your eyes and drift into unconsciousness—and for some individuals, the threat is so severe that they never awaken. An ancient Greek saying even compares death and sleep as siblings, with death representing the ultimate completion of sleep and sleep being an incomplete form of death.
Sleep has traditionally been viewed as a passive process our bodies undergo automatically. However, the reality is that our brains remain highly active during slumber. Additionally, many mysteries surrounding sleep persist, leaving modern scientists with much to uncover.
Interestingly, there are still astonishing (and occasionally alarming) occurrences when our conscious minds shut down and our bodies enter the sleep state. At times, the outcomes can be truly horrifying.
10. Sudden Cardiac Arrest

Sudden cardiac arrest (SCA) happens when the sinoatrial node, which functions as the heart's natural pacemaker, fails. This condition arises due to a malfunction in the heart's electrical system, and in severe cases, it can prove fatal within minutes.
How does it lead to death? It primarily cuts off blood supply to the brain. The most alarming aspect is that it can strike during sleep, and in half of the cases, there are no prior symptoms before the cardiac arrest happens.
9. Carbon Monoxide Poisoning

Carbon monoxide (CO) is an invisible, scentless gas that can be deadly when inhaled in large quantities. It is present in exhaust fumes from vehicles, stoves, grills, fireplaces, gas ranges, furnaces, and similar sources. Without a carbon monoxide detector, it is nearly impossible to detect.
How does it cause death? Essentially, if a significant amount accumulates in a confined area, inhaling it can become poisonous. Inhaling large quantities can be fatal, as the gas in your lungs can lead to irreversible consequences. If conscious, the victim might feel dizzy, weak, experience headaches, or suffer from nausea.
But what if it affects you while you're asleep? Those who are sleeping often show no symptoms and can pass away in their sleep.
8. Myocardial Infarction

A myocardial infarction, commonly referred to as a heart attack, can occur during sleep. Fortunately, there's a high likelihood that this type of cardiac event will wake the person before proving fatal.
Heart attacks occur when blood flow to a section of the heart is obstructed. This obstruction can damage or destroy part of the heart muscle.
How does it lead to death? If a significant portion of heart tissue is damaged, the heart may lose its ability to pump blood effectively to the rest of the body. This can cause heart failure, which may be fatal without immediate medical intervention.
Sadly, a person experiencing a heart attack while asleep is often unable to seek medical attention—and that’s what makes it so frightening.
7. Central Sleep Apnea

Central sleep apnea is a condition where breathing repeatedly stops and starts during sleep. It occurs when the brain fails to send the correct signals to the muscles responsible for breathing, often due to an issue in the brain stem.
How does it cause death? In severe cases, hypoxemia can develop, where oxygen levels in the body drop below what is necessary for survival. This results in oxygen deprivation, which can be fatal.
If the brain fails to wake the body in time to resume breathing, the outcome can be deadly.
SEE ALSO: Top 10 Surprisingly Common Ways To Die In Your Sleep
6. Unexplained Nocturnal Death Syndrome

This is undoubtedly one of the more enigmatic entries on our list.
Unexplained nocturnal death syndrome (SUNDS) was first documented in 1977 among Southeast Asian Hmong refugees in the United States and Canada. Since then, it has earned a fearsome reputation in both medical literature and the shadowy realms of the internet. In the Philippines, it’s known as Bangungut; in Hawaii, it’s called Dream Disease; and in Thailand, it’s referred to as lai tai, meaning 'sleep and die.'
The precise cause of death in SUNDS cases remains unknown, but the pattern is consistently similar. It typically results in the sudden, unexplained death of young, healthy individuals during sleep.
How does it cause death? The exact mechanism is still a mystery, but it is prevalent in Southeast Asia. Researchers propose various theories, including ion channel dysfunction and ventricular fibrillation.
5. Cerebral Aneurysm

A cerebral aneurysm, or brain aneurysm, is a weakened area in the wall of a brain blood vessel. It resembles a thin balloon that fills with blood. Over time, the constant blood flow weakens and enlarges the spot, and if the pressure becomes too great, it can rupture.
How does it lead to death? When an aneurysm bursts, the bleeding typically lasts only seconds. However, the blood damages nearby brain cells and raises pressure inside the skull. If this pressure becomes too high, it can swiftly become life-threatening.
4. Enterovirus D68

This entry is one of the lesser-known on our list, but it is no less alarming.
Enterovirus D68 (EV-D68) is a non-polio enterovirus first discovered in California in 1962. However, in 2014, there was a significant surge in reported cases, leading researchers to question whether the virus might become more widespread in the future than previously anticipated.
What makes EV-D68 frightening is that while it typically causes mild to severe respiratory symptoms, it can also be entirely asymptomatic. Despite this, medical experts warn that the virus could pose a greater threat in the US than Ebola.
How does it lead to death? It can trigger severe respiratory issues, often marked by a distinctive high-pitched wheezing sound, a hallmark of infection. Additionally, it has been linked to muscle weakness and inflammation of the spinal cord, which is arguably even more concerning than the respiratory symptoms.
While dying from an infection isn't common, the symptoms can sometimes be severe enough to be fatal—even if the person is asleep.
3. Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleep disorder where breathing repeatedly stops and starts during sleep. OSA is the most prevalent form of sleep apnea and is also the leading cause of sleep-related deaths.
This condition occurs when the airway is physically blocked, often due to relaxed throat muscles. The tongue, uvula, tonsils, and soft palate can also contribute to the obstruction. An estimated 22 million Americans have sleep apnea, but 80% of cases go undiagnosed, earning it the title of a 'silent killer.'
How does it cause death? OSA leads to sudden drops in blood oxygen levels during breathing pauses. For those already at risk of heart attacks, strokes, or heart failure, OSA can act as a trigger for these life-threatening events.
In such scenarios, death can occur before the victim even has the opportunity to wake up.
2. The Widowmaker Heart Attack

While most heart attacks often wake their victims before death strikes, the 'widowmaker' is a notable exception. Although heart attacks have been mentioned earlier, this specific type of infarction warrants its own entry.
Why? It is one of the most lethal forms of heart attacks. It occurs when the left main artery, or the left anterior descending artery, becomes completely blocked. A total blockage in this artery is almost invariably fatal without urgent medical intervention, earning it its ominous nickname.
How does it cause death? Severe blockages during a heart attack damage the heart muscle. If the muscle is too damaged to pump blood, the outcome can be deadly.
1. Dry Drowning

While most people know drowning in water is a risk, many are unfamiliar with the term 'dry drowning' and its implications. It’s a particularly terrifying way to die.
This phenomenon refers to a form of drowning that can happen even after the person has exited the water. Although it’s technically still drowning, the term 'dry drowning' has been adopted to describe it, though some doctors advocate for discontinuing its use.
It occurs when even a small amount of inhaled water passes the throat and enters the lungs. This often triggers symptoms, but they can be mild and easily overlooked.
The alarming aspect is that this water can lead to worsening breathing difficulties over time. In some instances, these issues don’t arise until hours or even days later—after the person has gone to sleep. While 'dry drowning' is rare compared to overall drowning deaths, it remains deeply unsettling.
How does it cause death? It essentially suffocates the victim by cutting off their oxygen supply until they can no longer breathe.